Heat exchanger structure for a plurality of electrochemical storage cells

ABSTRACT

A heat exchanger structure for a plurality of electrochemical storage cells has at least one duct component through which thermal control medium flows. The duct component has two material strips which are arranged parallel to one another and between which a heat exchanger duct is formed. The material strips have shaped portions adapted to the storage cells. The heat exchanger structure is useable, for example, for a motor vehicle battery.

[0001] The invention relates to a heat exchanger structure for aplurality of electrochemical storage cells, with at least one ductcomponent through which thermal control medium flows.

[0002] The patent specification DE 198 49 491 C1 discloses a device forthe thermal control of a plurality of electrochemical storage cells, inwhich heat exchanger ducts are arranged between a plurality of layers ofparallelepipedic storage cells. The heat exchanger ducts issue intodistributors and are connected to these to form a rigid grid-like frame.The heat exchanger ducts are designed as tubular elements of rectangularcross section and support the storage cells. To fix the storage cells,spacers are provided, which, within a layer of storage cells, retainthese at a predetermined distance from one another. Furthermore, DE 9002 249 U1 and EP 0 917 230 A1 each disclose a heat exchanger structurefor a plurality of electrochemical storage cells, with at least one ductcomponent through which thermal control media flow. In this case, theduct component of the heat exchanger structure disclosed from EP 0 917230 A1 has shaped portions adapted to the storage cells.

[0003] The invention is intended to provide a heat exchanger structurefor a plurality of electrochemical storage cells, which, along with asimple construction, allows a good thermal control of the individualstorage cells.

[0004] For this purpose, according to the invention, a heat exchangerstructure having the features of claim 1 is provided. By a heatexchanger duct being formed between two parallel material strips whichhave shaped portions adapted to the storage cells, the storage cells areheld by the duct component with a form fit. There is therefore no needfor any additional spacer or holding elements in order to secure thestorage cells against slipping out of place. By the material stripsengaging on the storage cells with a form fit, a large contact surfaceand consequently a good thermal control of the storage cells areobtained. The shaped portions, adapted to the storage cells, of thematerial strips may in this case be produced simply by the bending ofthe material strips or even during the manufacturing process.

[0005] Advantageous developments of the invention are specified in thesubclaims.

[0006] Since the duct component has supporting members arranged atadjacent longitudinal edges of the material strips and each having aspacer web extending between the material strips, a particularly simpleconstruction of the duct component from only four components, to beprecise two material strips and two supporting members, is obtained.With the aid of the spacer web extending between the material strips,the distance between the material strips arranged parallel to oneanother and consequently the cross section of the heat exchanger ductare defined.

[0007] A particularly simple mounting of the duct component is obtainedwhen the supporting member has a fixing web which extendsperpendicularly to the spacer web and which is adapted to the shapedportions of the material strips. The supporting member therefore merelyhas to be introduced between the material strips, until the longitudinaledges of the material strips butt against the fixing web. The supportingmember may in this case be produced in one piece with the spacer web andwith the fixing web, this being conducive to the simple construction ofthe heat exchanger structure.

[0008] A constant cross section of the heat exchanger duct can beensured in a simple way in that a spacer strip extending in thelongitudinal direction of the material strips is provided between thetwo material strips of the duct component in their middle region. Inthis way, for example, two heat exchanger ducts can also be produced inone duct component. The heat exchanger structure is suitable in aparticular way for being arranged between two layers of storage cellswhen the duct component has two heat exchanger ducts between twomaterial strips in each case, one heat exchanger duct lying on a topside and the other heat exchanger duct on an underside of the ductcomponent. The cooling ducts may in this case be symmetrical to oneanother, as a result of which, along with a simple construction, aforward flow and the return flow of the thermal control medium betweentwo layers of storage cells can be implemented. A contribution to asimple construction is made by the fact that two one-piece supportingmembers are provided, which connect the four material strips of the twoheat exchanger ducts at their adjacent longitudinal edges in each case.Even when two heat exchanger ducts are provided for each duct component,the latter can be assembled in a simple way from four material stripsand two supporting members.

[0009] One design of the heat exchanger structure is advantageous inthat two duct components for receiving at least one storage cell arearranged opposite one another and in such a way that shaped portionsextending in contra-directional directions are located opposite oneanother. This ensures not only a secure hold of a storage cell in thecontra-directed shaped portions located opposite one another, but alsothe good thermal control, for example cooling, of the said storage celldue to a large contact surface between the heat exchanger ducts and thestorage cell. Such a design also makes it possible to have aparticularly space-saving arrangement of the storage cells in aplurality of layers, the individual layers of storage cells beingcapable of being offset to one another with the effect of a particularlycompact arrangement.

[0010] When a plurality of duct components are arranged essentially inone plane and parallel to one another, adjacent end faces of the ductcomponents being connected to a distributor, a planar module isobtained, which can be arranged between two layers of storage cells forthe thermal control and fixing in position of the latter. The heatexchanger ducts are connected to distributor ducts in the distributors,and, when two heat exchanger ducts through which the flow passescontra-directionally are provided for each duct component, twodistributors are likewise provided in the distributor component.

[0011] A particularly expedient modular configuration is obtained by theprovision of at least two distributors which are connected by means ofat least one fixing element running parallel to the duct components. Astable and flat module is thereby provided, in which the distributors inthe storage cells are secured additionally by the fixing element. Whenthree fixing elements are provided for each module, this results in astable frame consisting of the distributors and of the fixing elementsarranged at the ends and in the middle of the distributors. The ductcomponents can consequently be of particularly lightweight design, sincethe frame is formed from the distributors and the fixing elements andthe duct components therefore no longer have to assume a supportingfunction. The fixing element in this case also serves for securing thestorage cells in the longitudinal and transverse directions of theframe. A plurality of such modules may be arranged one above the otherin layers, in order, together with the storage cells, to form a stablecomposite structure.

[0012] For the thermal control of cylindrical storage cells, what areknown as round cells, there is provision for the shaped portions of thematerial strips to have the form of cylinder segments. When, as seen inthe longitudinal direction, the material strips have shaped portionswith alternately contra-directional curvatures, a wavy shape of thematerial strips is obtained. When layers of storage cells are arrangedin each case so as to be offset by the amount of half the wavelength ofthe wavy shape, a very high packing density of the storage cells, at thesame time with good thermal control and good fixing in position of thestorage cells, can be achieved. Particularly good thermal control of thestorage cells by means of a large contact surface of the heat exchangerducts with the storage cells is obtained when, as seen in thelongitudinal direction, the material strips have shaped portions withco-directional curvatures. Such a design is particularly suitable for anon-offset arrangement of the individual layers of the storage cells inrelation to one another.

[0013] The object on which the invention is based is also achieved bymeans of an electrochemical energy store having the features of claim12. In such an energy store, the storage cells are arranged in aplurality of parallel layers, thus resulting in a simple and compactconstruction of the energy store, along with a secure fixing and goodthermal control of the storage cells.

[0014] A particularly compact construction of the energy store can beachieved when the thermal control medium between a first and a secondlayer of storage cells flows contra-directionally to the thermal controlmedium between the second and a third layer of storage cells. In such anarrangement, only one layer of heat exchanger ducts is necessary betweentwo layers of storage cells, so that a flat construction of the energystore is obtained.

[0015] A particularly uniform thermal control of the storage cells ofthe energy store is obtained when the thermal control medium flows intotwo contra-directional directions between two layers of storage cells inheat exchanger ducts separated from one another. By virtue of thecontra-flow of the thermal control medium between two layers, aninsufficient cooling or thermal control of storage cells lying fardownstream is avoided.

[0016] Further features and advantages of the invention are specified inthe following description, with reference to the accompanying drawingsin which:

[0017]FIG. 1 shows a perspective partially sectional view of an energystore and of a heat exchanger structure according to a first embodimentof the invention,

[0018]FIG. 2 shows a perspective partially sectional view of the heatexchanger structure shown in FIG. 1,

[0019]FIG. 3 shows a partial side view of a duct component used in theheat exchanger structure of FIG. 2,

[0020]FIG. 4 shows an enlarged top view of the end face of the ductcomponent of FIG. 3,

[0021]FIG. 5 shows an enlarged sectional view along the line V-V of FIG.3,

[0022]FIG. 6 shows a partial longitudinal section of the duct componentof FIG. 3,

[0023]FIG. 7 shows a sectional view of an energy store according to thefirst embodiment of the invention,

[0024]FIG. 8 shows a partial top view of the energy store of FIG. 7,

[0025]FIG. 9 shows a sectional view of an energy store according to asecond embodiment of the invention,

[0026]FIG. 10 shows an enlarged illustration of the detail X of FIG. 9,

[0027]FIG. 11 shows a partial side view of a first duct component ofFIG. 10,

[0028]FIG. 12 shows an enlarged sectional view along the line XII-XII inFIG. 11,

[0029]FIG. 13 shows a partial side view of a second duct component inFIG. 10, and

[0030]FIG. 14 shows an enlarged sectional view along the section XIV-XIVin FIG. 13.

[0031] The electrochemical energy store illustrated in FIG. 1 has aplurality of storage cells 10 which are arranged one above the other intwo parallel layers 12 and 14. Between the layers 12 and 14 is arrangeda heat exchanger structure which is used as a cooling device and has afirst distributor 16 and a second distributor 18. The distributors 16and 18, in each of which a distributor duct is arranged, lie parallel tothe cylindrical storage cells 10 on the longitudinal sides of the layer12. The distributors 16 and 18 are connected by means of a plurality ofcooling-duct components 20 arranged parallel to one another. Adjacentend faces of the cooling-duct components 20 are connected to thedistributor 16 or to the distributor 18. The distributor duct of thedistributor 16 is consequently flow-connected to the distributor duct inthe distributor 18 via heat exchanger ducts acting as cooling ducts andlocated in the cooling-duct components 20. The distributors 16 and 18are also connected to one another by means of fixing elements 22, 24, 26and 28. The fixing elements 22, 24, 26 and 28 form, with thedistributors 16 and 18 and the cooling-duct components 20, a stableframe-like cooling module 30. Whilst the cooling module 30 is arrangedbetween the layers 12 and 14 of the storage cells 10, a further coolingmodule 32, which is essentially structurally identical to the coolingmodule 30, is arranged below the layer 14 of storage cells. The energystore shown in FIG. 1 can be extended in a simple way by a furthercooling module being placed onto the layer 12 of storage cells 10.

[0032] The illustration in FIG. 2 shows the cooling module 30 of FIG. 1.The distributor 16 is provided at one end with a connection piece 34,via which cooling liquid as a thermal control medium can pass into thedistributor duct 36 in the distributor 16. The cooling liquid passes outof the distributor duct 36 into the cooling ducts in the cooling-ductcomponents 20 and flows through these into the distributor duct in thedistributor 18. The cooling liquid leaves the cooling module 30 via aconnection piece 38 of the distributor 18, the said connection piecebeing arranged diagonally opposite the connection piece 34.

[0033] The fixing elements 22, 24, 26 and 28 engage on the distributors16 and 18 solely on the lower and lateral surfaces of the latter. Thefixing elements 22, 24, 26 and 28 can therefore be pushed onto thedistributors 16 and 18 from below. The fixing element 22 has a segment40 which serves for fixing the storage cells in the lateral direction.For this purpose, the web-like segment 40 is provided with recesseswhich are in the form of a circle segment and into which the cylindricalstorage cells are inserted and consequently secured against slipping outof place. A further segment 42 of the fixing element 22 serves mainlyfor securing the storage cells in the longitudinal direction and, forthis purpose, has a web 46 at the end of a recess 44 in the form of acylinder segment. The fixing element 28 arranged at the opposite end ofthe distributors 16 and 18 is constructed identically to the fixingelement 22, in exactly the same way as the fixing elements 24 and 26 inthe middle of the distributors 16, 18. However, the fixing elements 24and 26 in the middle of the distributors 16 and 18 may also be connectedto form a single one-piece component. The fixing elements 22, 24, 26 and28 of the cooling module 30 have on their top side the recesses 40 and44 and on their underside corresponding recesses for the layer ofstorage cells which is arranged underneath. Such recesses on theunderside of the fixing elements can be seen at the partiallysectionally illustrated fixing element 28 and are designated by thereference symbol 48.

[0034] It can be seen clearly from the side view of FIG. 3 that, as seenin the longitudinal direction, the cooling-duct component 20 has shapedportions 50, 52 with alternately contra-directional curvatures, thusresulting in a wavy shape of the cooling-duct component 20. The shapedportions 50 and 52 are adapted to the cylindrical shape of the storagecells 10.

[0035] As may be gathered from the top view of FIG. 4 and from thesectional view of FIG. 5 along the line V-V in FIG. 3, the cooling-ductcomponent 20 has two material strips 54 and 56 which are arrangedparallel to one another. Supporting members 58 and 60 are arranged atadjacent longitudinal edges of the material strips 54 and 56. Thesupporting members 58, 60 each have a spacer web 62 which extendsbetween the material strips 54, 56. The material strips 54 and 56 cometo bear respectively on the top side and the underside of the spacerwebs 62, so that the said material strips are arranged at a defineddistance from and parallel to one another. The supporting members 58, 60also each have a fixing web 64 which is arranged perpendicularly to thespacer web 62. For mounting the cooling-duct component 20, thesupporting members 58, 60 are pushed in between the material strips 54,56 until their longitudinal edges butt against the fixing web 64.

[0036] A spacer strip 66 is arranged centrally to the supporting members58, 60 between the material strips 54, 56. With the aid of the spacerstrip 66, the distance between the material strips 54, 56 is keptconstant over their entire width. The cross section of the cooling ducts68 and 70 formed between the material strips 54, 56 is consequently alsoconstant over the entire length of the cooling-duct component 20. By thematerial strips 54, 56 coming to bear respectively on the top side andthe underside of the spacer web 62 and, with their longitudinal edges,against the fixing web 64, the cooling ducts 68, 70 have a defined crosssection, without difficult adjustments having to be carried out duringthe mounting of the cooling-duct component 20.

[0037] The wavy profile of the material strips 54, 56 can be seenclearly in the sectional view of FIG. 6 along the line VI-VI of FIG. 4.The material strips 54, 56 are arranged parallel to one another overtheir entire length and between them form the cooling duct 70. The wavyshape of the material strips can be achieved, for example, simply by thebending of the material strips or by the shaping of the material stripsduring the production process. In the embodiment illustrated, the heatexchanger structure consists of polycarbonate plastic.

[0038] The sectional view of FIG. 7 illustrates an energy storeaccording to the invention which has five parallel layers of storagecells 10. Each layer of storage cells 10 is received between two coolingmodules, such as were described in connection with FIGS. 1 to 7. Theindividual layers of storage cells 10 are in each case offset relativeto one another by the amount of half a wavelength of the wavycooling-duct components 20. As can be seen in FIG. 7, a highly compactarrangement of the storage cells is thereby obtained, in which acooling-duct component 72 arranged between two layers engagesalternately with storage cells of a first layer 74 arranged above andwith storage cells of a second layer 76 arranged below. The cooling-ductcomponents 72, 78 are connected to a distributor 80 on each of their endfaces. The distributor ducts arranged in the distributors 80 areconnected via connecting lines 82 to one another and to the coolingducts in the cooling-duct components 72, 78 in such a way that thecooling liquid changes direction from plane to plane. Thus, the coolingliquid in the cooling-duct component 72 between the first layer 74 andthe second layer 76 flows contra-directionally to the cooling liquid inthe cooling-duct component 84 between the second layer 76 and a thirdlayer 86. The storage cells in the individual layers 74, 76, 86 arethereby cooled uniformly, irrespective of their position within a layer.

[0039] The distributors 80 and the cooling-duct components 78 arrangedparallel to one another and connecting the distributors 80 can be seenin the top view, shown in FIG. 8, of the energy store of FIG. 7.Contacts 88, via which the individual storage cells 10 can be connectedto one another, are accessible on the end faces of the storage cells 10.

[0040] An energy store, illustrated in section in FIG. 9, according to asecond embodiment of the invention has four layers of storage cells 10,the said layers being arranged parallel to one another. In contrast tothe first embodiment illustrated in FIGS. 7 and 8, the parallel layers90, 92, 94 and 96 are not arranged so as to be offset to one another.Cooling-duct components 98, 100 and 102 arranged between two layers 90,92, 94 and 96 have in each case two cooling ducts for each cooling-ductcomponent 98, 100 and 102. Only the lowermost cooling-duct component 104and the uppermost cooling-duct component 106 have only one cooling ductin each case.

[0041]FIG. 10 illustrates, enlarged, the detail X of the energy storeillustrated in FIG. 9. The cooling-duct component 104 has materialstrips 108 and 110 which are arranged parallel to one another andbetween them form a cooling duct 112. The shaped portions of thematerial strips 108, 110 have the form of cylinder segments. Thematerial strip 108 of the cooling-duct component 104 thereby engages onthe storage cells 10 of the layer 96 with a form fit. As seen in thelongitudinal direction of the material strips 108, 110, the materialstrips 108, 110 have shaped portions with co-directional curvatures. Thecooling-duct component 102 arranged between the layers 94 and 96 has twocooling ducts 114 and 116, through which the cooling liquid flows incontra-directional directions. In the region of a plane 118 between thelayers 94 and 96, a cooling-liquid contra-flow is thereby obtained, withthe result that a particularly uniform thermal control of the storagecells 10 is possible. The cooling duct 114 issues into a distributorduct 120, and, as seen in the flow direction of the cooling liquid, thecooling duct 116 emanates from a distributor duct 122. The cooling duct112 issues into a distributor duct 124.

[0042]FIGS. 11 and 12 illustrate the cooling-duct component 102 in moredetail. The sectional view of FIG. 12 along the line XII-XII in FIG. 11shows the construction of the cooling-duct component 102 from fourmaterial strips 126, 128, 130 and 132 and two supporting members 134 and136. The supporting member 134 is produced in one piece and, by means ofthe spacer web 138, holds the material strips 126 and 128 at a defineddistance from and parallel to one another. A spacer web 140 of thesupporting member 134 holds the material strips 130 and 132 at a defineddistance from and parallel to one another. The supporting member 136 isconstructed identically to the supporting member 134.

[0043] The views of FIGS. 13 and 14 show detailed views of thecooling-duct component 104. In the sectional view of FIG. 14 along theline XIV-XIV of FIG. 13, it can be seen that the material strips 108 and110 are held at a constant distance from and parallel to one another bymeans of two supporting members 142 and 144.

1. Heat exchanger structure for a plurality of electrochemical storagecells (10), with at least one duct component (20; 72, 78, 84; 102, 104,106) through which thermal control medium flows, and in which the ductcomponent (20; 72, 78, 84; 102, 104, 106) has shaped portions (50, 52)adapted to the storage cells (10), characterized in that the storagecells (10) are arranged in a plurality of parallel layers (12, 14; 74,76, 86; 90, 92, 94, 96), the thermal control medium in the respectiveduct component (20; 72; 100) between a first and a second layer (12, 14;74, 76; 92, 94) of storage cells (10) flowing contra-directionally tothe thermal control medium in the respective duct component (84; 102)between the second and a third layer (76, 86; 94, 96) of storage cells(10) and/or in a duct component (20) closing off the second layer (14).2. Heat exchanger structure according to claim 1, characterized in thatthe duct component (20; 72, 78, 84; 102, 104, 106) has material strips(54, 56; 108, 110, 126, 128, 130, 132) which are arranged parallel toone another and between them form a heat exchanger duct (68, 70; 112,114, 116).
 3. Heat exchanger structure according to claim 2,characterized in that the duct component (98, 100, 102) between twolayers (90, 92, 94, 96) of storage cells (10) is formed from two heatexchanger ducts (114, 116) separated from one another.
 4. Heat exchangerstructure according to claim 2 or 3, characterized in that the thermalcontrol medium flows between two layers (94, 96) of storage cells (10)in two contra-directional directions in the heat exchanger ducts (114,116) separated from one another.
 5. Heat exchanger structure accordingto one of claims 2 to 4, characterized in that the duct component (20;72, 78, 84; 102, 104, 106) has supporting members (58, 60; 134, 136,142, 144) arranged at adjacent longitudinal edges of the material strips(54, 56; 108, 110, 126, 128, 130, 132) and each having a spacer web (62;138, 140) extending between the material strips.
 6. Heat exchangerstructure according to claim 5, characterized in that the supportingmember (58, 60; 134, 136, 142, 144) has a fixing web (64) which extendsperpendicularly to the spacer web (62; 138, 140) and which is adapted tothe shaped portions (50, 52) of the material strips (54, 56; 108, 110,126, 128, 130, 132).
 7. Heat exchanger structure according to one ofclaims 2 to 6, characterized in that a spacer strip (66) extending inthe longitudinal direction of the material strips (54, 56) is providedbetween the two material strips (54, 56) of the duct component (20) intheir middle region.
 8. Heat exchanger structure according to one ofclaims 2 to 7, characterized in that the duct component (102) has twoheat exchanger ducts (114, 116) between two material strips (126, 128,130, 132) in each case, one heat exchanger duct (114) lying on a topside and the other heat exchanger duct (116) on an underside of the ductcomponent (102), and in that two one-piece supporting members (134, 136)are provided, which connect the four material strips (126, 128, 130,132) of the two heat exchanger ducts (114, 116) in each case at theiradjacent longitudinal edges.
 9. Heat exchanger structure according toone of the preceding claims, characterized in that two duct components(20; 72, 78, 84; 102, 104, 106) for receiving at least one storage cell(10) are arranged opposite one another and in such a way that shapedportions extending in contra-directional directions are located oppositeone another.
 10. Heat exchanger structure according to one of thepreceding claims, characterized in that a plurality of duct components(20; 72, 78, 84; 102, 104, 106) are arranged essentially in one plane(118) and parallel to one another, and adjacent end faces of the ductcomponents (20; 72, 78, 84; 102, 104, 106) are connected to adistributor (16, 18).
 11. Heat exchanger structure according to claim10, characterized in that at least two distributors (16, 18) areprovided, which are connected by means of at least one fixing element(22, 24, 26, 28) running parallel to the duct components (20).
 12. Heatexchanger structure according to one of claims 2 to 11, characterized inthat the shaped portions (50, 52) of the material strips (54, 56; 108,110, 126, 128, 130, 132) have the form of cylinder segments.
 13. Heatexchanger structure according to one of claims 2 to 12, characterized inthat, as seen in the longitudinal direction, the material strips (54,56) have shaped portions (50, 52) with alternately contra-directionalcurvatures.
 14. Heat exchanger structure according to one of claims 2 to12, characterized in that, as seen in the longitudinal direction, thematerial strips (108, 110, 126, 128, 130, 132) have shaped portions withco-directional curvatures.
 15. Use of a heat exchanger structureaccording to one of the preceding claims for an electrochemical energystore, in particular for a vehicle, with a plurality of storage cells(10).